Pad printing of components has not been widely used in the electronics field because the ink processes and equipment were poorly suited to the electronics manufacturing field.
There are two traditional ink marking processes that are similar to one another, namely, the direct marking process and the dry offset. The direct marking process is a very slow process and is accomplished both by machinery and manually, where a raised image plate is coated with a thin film of ink which is applied directly to the device surface. In the direct marking process crude tools are sometimes used.
The dry offset marking process is used by almost one hundred percent of today's marking equipment. In this method, a raised image printing plate is coated with a film of ink. This film is transferred to a rubber surface (offset surface). The film is again transferred to the device to be marked.